Is it obligatory to make up missed prayers when their number is unknown after repentance and starting to pray regularly?

Neglecting prayer out of laziness is a grave sin and a major iniquity, requiring repentance. Some jurists have even considered it an act of apostasy that expels one from the faith. We advise the questioner to make up all the missed prayers, whether they were missed intentionally, out of ignorance, or forgetfulness. This is the view of the majority of scholars. If one can determine the number of missed prayers, they should make them up. If the number is unknown, they should make up what they believe is most likely due.